This invention relates to the handling of cotton between the fields and the textile mills. More particularly, it relates to a method of operating a cleaning and ginning plant to produce blends of lint cotton for delivery to the textile mills.
As known to those skilled in the cotton industry, cotton plants produce seedpods, known as cotton bolls, which contain the seeds. Seed hairs, or fibers, growing from the outer skin of the seeds, become tightly packed within the boll, which bursts open upon maturity, revealing soft masses of the fibers. These fibers are white to yellowish white in color, range from about 0.75 to about 1.5 inches in length and are composed of about 85-90% cellulose, a carbohydrate plant substance; five to eight percent water; and four to six percent natural impurities.
Cotton is harvested when the bolls open. In the fields, the cotton bolls are tightly compressed into large modules which are transported from the fields to processing plants. In the processing plants, the modules are mechanically dispersed into clumps and then the fibers are separated from the seeds and are cleaned and then are further processed, ultimately into yarns.
It is known to disperse the cotton boll modules by use of a stack of rolls that include fingers which rotate into an advancing end of a cotton module, to tear loose clumps of the bolls from the module as they rotate. The stack of rolls is termed a disperser and it is common to use conveyors for delivering the cotton modules to the disperser. Example disperser systems are disclosed by the following United States Patents: U.S. Pat. No. 4,497,085, granted Feb. 5, 1985 to Donald W. Van Doorn, James B. Hawkins, Tommy W. Webb and William A. Harmon, Jr.; U.S. Pat. No. 5,121,841, granted Jun. 16, 1992, to Keith Harrington and Donald Rogers; U.S. Pat. No. 5,222,675, granted Jun. 29, 1993, to Jimmy R. Stover; U.S. Pat. No. 5,340,264, granted Aug. 23, 1994, to Manfred W. Quaeck and U.S. Pat. No. 5,469,603, granted Nov. 28, 1995, to Jimmy R. Stover. These patents show examples of the conveyors which have been used, or proposed, for delivering the cotton modules to the disperser. The present invention is not limited to any particular type of conveyor. However, a reciprocating slat conveyor is advantageous and preferred. Example reciprocating slat conveyors that are suitable are disclosed by U.S. Pat. No. 5,934,445, granted Aug. 10, 1999, to Raymond Keith Foster, Randall M. Foster and Kenneth A. Stout, and U.S. Pat. No. RE 35,022, granted Aug. 22, 1995, to Raymond Keith Foster.
Cotton fibers may be roughly classified into three main groups, based on staple length (average length of the fibers in a cotton module) and appearance. The first group includes the fine, lustrous fibers with staple length ranging from about 1 to about 2.5 inches and includes types of the highest qualityxe2x80x94such as Sea Island, Egyptian and Pima cottons. Least plentiful and most difficult to grow, long-staple cottons are costly and are used mainly for fine fabrics, yarns and hosiery. The second group contains the standard medium-staple cotton, such as American Upland, with staple length from about 0.5 to 1.3 inches. The third group includes the short-staple, coarse cottons, ranging from about 0.375 to 1 inch in length, used to make carpets and blankets, and to make coarse and inexpensive fabrics when blended with other fibers. Within each group, the quality of the fibers can vary depending on such things as where the cotton is grown. It is desirable to blend the lower quality fibers with higher quality fibers to produce an acceptable quality blend of fibers.
It is an object of the present invention to provide a method for blending cotton clumps as they are removed from the cotton modules. The clumps of bolls are mixed together to form the blend and then the blend is further processed to separate the fibers from the seeds, etc.
It is customary to disperse, clean and gin the cotton modules as they are brought from the fields to the ginning plant. Herein the term xe2x80x9cfield lotxe2x80x9d is used to mean a common quality of cotton usually from a particular field, or a region of a particular field, or two or more regions or fields in which the quality of the cotton is substantially the same. It is common practice to harvest the field lots and bring the modules to the ginning plant and there disperse the modules as they are received and collect and clean and gin the cotton clumps. At the end of the ginning operation the cotton lint is packed into bales and the bales are marked so as to identify the type and/or quality of cotton lint that each bale contains. Eventually the bales are delivered to textile mills where they are formed into thread that is used for making cloth. Presently, when it is desired to blend together two or more different kinds or qualities of cotton lint, the blending is done at the textile mill. Measured quantities of cotton lint are removed from bales that differ in kind and/or quality and the lint from the several bales is mixed or blended together and then the blend is processed to form the thread.
The co-pending applications of Raymond Keith Foster and Mark Jay Beason, Ser. No. 09/654,144, filed Sep. 1, 2000, and entitled Method And Apparatus For Mixing Textile Fibers And Particulate Material, and their later filed copending application Ser. No. 09/782,571, filed Feb. 13, 2001, and entitled Method And Apparatus For Blending Textile Fibers, disclose methods and apparatus for blending cotton boll clumps at the disperser station, with blending continuing in the cleaning and ginning plant, so as to produce a blend of cotton lint at the ginning plant that are delivered to the textile mills. The present invention utilizes some of the method and apparatus concepts that are disclosed in those applications.
The process-of the present invention includes receiving a plurality of cotton boll modules from a plurality of cotton field locations, to provide a plurality of field lots. A sample of cotton modules is selected from each field lot. Each sample and the field lot from which it came are identified and information data is generated associating each sample with its field lot. The field lot samples are separately processed to produce cotton lint. The cotton lint is then assayed to determine a relative quality. of the lint in each field lot sample. The assay information is used to establish a formula for blending cotton boll clumps from a plurality of field lots of different quality in order to form a cotton boll blend of a desired intermediate quality. The identification data is used for locating modules to be blended in storage. The located modules are introduced into dispersers and the dispersers are used to disperse cotton boll clumps from the modules in amounts necessary to form the desired amount of the desired blend of cotton boll clumps. The cotton boll clumps that are dispersed from the modules are mixed to form a blend of cotton boll clumps. The blend of cotton boll clumps is then cleaned and ginned so as to form a cotton lint blend.
It is within the scope of the present invention to store the identified field lots of cotton boll modules until the modules are to be selected to form a desired cotton lint blend. The selected modules are removed from storage and are then dispersed to form cotton boll clumps. The cotton boll clumps are blended, cleaned and ginned to form a desired cotton lint blend. Preferably, this is done in response to the receipt by the ginning plant of an order for a desired cotton lint blend from a customer. The cotton lint blend may be delivered to the textile mill customer, substantially immediately following its production so that storage is not necessary.
In a preferred embodiment of the invention, the modules are dispersed at a dispersing station that is located at the ginning plant. A conveyor is used for delivering and further blending the cotton boll clumps as they are moved from the disperser station to at least one cleaning unit and at least one cotton gin in the ginning plant.
Preferably, at least one pair of first and second confronting dispersers are provided at the disperser station.
Each disperser has an input side and an output side. The output sides face each other on opposite sides of a mixing zone. The first and second dispersers are operated while a first cotton boll module is conveyed against the input side of the first disperser and a second cotton boll module is fed against the input side of the second disperser. The first and second dispersers are operated so that each will disperse cotton boll clumps from its module and deliver them into the mixing zone in admixture with cotton boll clumps from the other dispenser of the pair. The mixture of cotton boll clumps is collected and is conveyed away from the dispenser station into and through the cleaning and ginning operation.
In preferred form, a conveyor (e.g. an airstream conveyor) is used for conveying the blend of cotton boll clumps during at least of a part of their travel from the disperser station to the cleaning and ginning operation, so that the cotton boll clumps are further blended (e.g. fluidized) as they are being conveyed.
The present invention includes storing the identified field lots of cotton boll modules until it is desired to form a particular cotton lint blend. Then, cotton boll modules are selected from the identified lots in storage and are moved to the dispersing station and are then dispersed and/or mixed.
Preferably, each disperser is provided with an infeed conveyor. The selected modules are removed from storage and are placed onto the infeed conveyors. Then, the conveying speeds of the infeed conveyors are controlled so as to control the dispersion rate of the cotton boll clumps and thus the content of the blend.
According to a desired aspect of the invention, cotton boll clumps from diverse field lots are further mixed and blended as they are moved from the disperser station to cleaning units and cotton gins in the ginning plant. Also, there is further mixing and blending of the cotton boll clumps in the cleaning units. There is still more mixing and blending of the cotton boll clumps in the cotton gin.
The present invention includes positioning more than two dispensers at the dispenser station, each having an input side and an output side. Cotton boll clumps are dispersed from each cotton boll module and the clumps are mixed and blended before being conveyed to the cleaning and ginning operation.
It is also within the scope of the invention to dispensers that are positioned side-by-side. The dispersers are used to disperse cotton boll clumps from-diverse modules. The clumps are then collected and are mixed together to form a blend of cotton boll clumps.
A further aspect of the invention is to use the cotton lint produced by processing the field lot samples to establish a market price for each field lot. Then, this market price information is used to help establish a formula for blending cotton from the various field lots to produce a desired blend to be sent to a textile mill.
Other objects, advantages and features of the invention will become apparent from the description of the best mode set forth below, from the drawings, from the claims and from the principles that are embodied in the specific structures that are illustrated and described.